1. Field of the Invention
This invention relates to a semiconductor integrated circuits device and more particularly, to a semiconductor integrated circuit device having voltage level converting circuits for converting the voltage level of a signal generated in one of circuit blocks driven at different power source voltages so as to meet the power source voltage of the other circuit block.
2. Description of the Prior Art
A layout example of a conventional semiconductor integrated circuit device having a voltage level containing circuit as shown above is shown in FIG. 1.
In FIG. 1, an interface region 2 is provided on a semiconductor substrate so as to surround an internal circuit block 1 and other internal circuit blocks (not shown), and a wiring region 3 is provided between these internal circuit blocks and the interface, region 2. The internal circuit block 1 is driven at a first power source voltage VI and has a macro-block 7 consisting of circuits driven at a second power source voltage V2.
The interface region 2 has interface blocks 2a disposed in a row and, in the wiring region 3 are disposed surrounding lines 4 and 5 for supplying the first source voltage V1. The surrounding line 4 is supplied with the first source voltage V1 from a first external power source (now shown) and the surrounding line 5 is connected to the earth. The circuits other than the macro-block 7 of the internal circuit block 1 are supplied with the first source voltage V1 through the surrounding lines 4 and 5.
The macro-block 7 has a surrounding line 7a for supplying the second power source voltage V2 to the internal circuits of the macro-block 7 and a voltage level converting circuit 7b for converting the voltage level between a signal generated in the internal circuit block 1 and a signal generated in the macro-block 7 in response to the first and second source voltages V1 and V2.
In the interface region 2 near the macro-block 7, interface blocks 9a and 9b for the second source voltage V2 are disposed which are connected to the surrounding line 7a, respectively, through wiring lines 8a and 8b disposed in the wiring region 3. The internal circuits of the macro-block 7, including the voltage level converting circuit 7b, are supplied with the second source voltage V2 through the interface blocks 9a and 9b, wiring lines 8a and 8b and surrounding wiring line 7a from a second external power source (not shown).
In the circuit layout shown in FIG. 1, the circuits driven by the second power source voltage V2 are collected in the block macro-7 together with the surrounding line 7a for supplying the power source voltage V2 thereto are and disposed within the internal circuit block 1 driven by the first power source voltage V1.
FIG. 2 shows another layout example of a conventional se miconductor integrated circuit device having a voltage level converting circuit.
In FIG. 2, an interface region 12 is provided so as to surround an internal circuit block 11 and other internal circuit blocks (not shown). The interface region 12 has interface blocks 12a and an interface block 17 in which a voltage level converting circuit 17b is disposed. In this example, the voltage level converting circuit 17b is not disposed in the macro-block 7 as in the preceding example but in the interface region 12.
The first power source voltage V1 is supplied through surrounding lines 14 and 15 disposed in a wiring region 13 to the internal circuit block 11 and other internal circuit blocks (not shown), and the second power source voltage V2 is supplied as shown in the example of FIG. 1. A signal of the circuit driven by the first source voltage V1 in the internal circuit block 11 and a signal of the circuit driven by the second source voltage V2 in the internal circuit block 11 are sent to the voltage level converting circuit 17b to be subjected to the voltage level conversion.
As mentioned above in, the layout of FIG. 2 the voltage level converting circuit 17b is provided in the interface region 12.
With the conventional devices as discussed above, the voltage level converting circuit is disposed in the macro-block or interface region and, as a result, if the layout of the integrated circuit is changed, the arrangement and wiring of the voltage level converting circuit are to be changed according. Thus, the integrated circuit itself is to be newly designed either entirely, or at least the macro-block is to be newly designed. As a result, there arises such a problem that not only it takes a lot of time for layout designing, but also the layout itself may contain to an error.
Particularly, in case that all internal circuit blocks are driven at the first power source voltage and all interface blocks are driven at the second power source voltage, a large number of voltage level converting circuits would be required and the above-mentioned problem will most apparently occur.